<html xmlns="http://www.w3.org/1999/xhtml" xmlns:html="http://www.w3.org/1999/xhtml">
<head>

<bindings xmlns="http://www.mozilla.org/xbl">
  <binding id="lub4">
    <content>
      <html:span style="color: green;">
        <children/>
      </html:span>
    </content>
  </binding>
</bindings>


</head>

<body onload="document.getElementById('gogo');">
  <span style="-moz-binding: url('#lub4')"><div/><em id="gogo">I</em></span>
</body>

</html>